You will be given levofloxacin once a day by mouth or vein until your white blood cell count rises. You will receive filgrastim through a needle under the skin once a day until your white blood cell count rises. You will begin to receive fluconazole on Day 0 by mouth until your white blood cell count rises. You will also take trimethoprim and sulfamethoxazole (SMX) by mouth 2 times a day, beginning on Day -7 and continuing for at least 3 months after chemotherapy.